Pulmonary hypertension (PH) is a significant complication frequently developed in patients with interstitial lung disease (ILD). So far, survival benefit of pulmonary vasodilators (PVDs) in patients with PH associated with lung disease is limited. In this study, we have explored prognostic factors of the effect of pulmonary vasodilators (PVDs) in patients with PH associated with ILD (PH-ILD).

Clinical charts of PH-ILD patients who started to take PVDs between Apr. 2007 and Oct. 2022 were retrospectively reviewed. PH was determined by mPAP>20 mmHg confirmed by right heart catheterisation within 1 year before the initiation of PVDs.

There were 128 patients who met the inclusion criteria. The median age was 67 years and 64% were male. Idiopathic pulmonary fibrosis (IPF) was dominant (40%) followed by connective tissue disease-related ILD (30%). The medians of each parameter were: FVC, 68%pred.; DLCO, 31%pred.; mPAP, 31 mmHg; PVR, 4.25 Wood units; PAWP, 10 mmHg; CI, 2.82 L/min/m2; BNP, 42.0 pg/mL; 6-minute walk distance (6MWD), 308 m. WHO functional class I/II/III/IV was 1/54/31/28 cases each. The median survival time (MST) was 22.2 months, and 1-year survival was 62%. Females, non-IPF diagnosis, longer baseline 6MWD, lower BNP, and higher ?6MWD/3 months were independently associated with longer survival. ?6MWD of -50 m/3 months was the best cutoff for predicting 2-year mortality (sensitivity 0.399, specificity 0.912) and gave the best c-index to the survival prediction model.

ILD subtype was important for predicting survival of PH-ILD treated with PVDs. In addition, baseline and longitudinal change in 6MWD were also robust prognostic factors.